Correct, C0RR0SIVE. Warning: wall of text incoming.
The inability to see a modem remotely can be caused by a number of different things or a combination of some of them. I'll list what I consider to be the top three.
1. The radio mounted on the arm of the dish is a newer design from our Gen3 radios. The uplink and downlink are separated from each other. The "Uplink" or "Transmit" is very, very sensitive because it has to bounce off the dish and make its way up to the satellite, leaving little room for blockage or error. If the signal cannot make it up to the satellite, we can't talk to it.
2. Low power, dirty power or insufficient power distribution. I've helped customers in the past who have had an array of weird interference, but sharing the outlet with a major appliance is pretty common. Refridgerators, washers/dryers, space heaters, even coffee makers (mine makes my lamp flicker at home). Using a surge protector or strip that does not supply sufficient power to the modem is also common. Not only does the modem need power, but it also provides power to the radio outside. Dirty power is less common, but sometimes they do crop up. Rural areas with older infrastructure encounter this problem and it is very hard to fix.
3. Failed or faulty hardware is another reason. Since the two directions of signals are separated, one can fail while the other does not. This is a little less likely and you would have probably noticed the system performance degrading over time.
Just based on some of the historical data I have on your system I've made a guess at one of these being the problem. It is possible that a coaxial cable frayed, corroded or is just loose somewhere. The timing sync between the satellite and your modem could be off. Hopefully the tech can find the definitive root cause of this so we can help diagnose this kind of issue again in the future.
~Amanda
